alexa_create_timer

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare that this is a non-read-only, non-destructive, open-world write; the description adds the materially important behavioral fact that the tool is gated behind a user confirmation, and details both confirmation modes including the fallback token flow. That is exactly the kind of trait an agent must know before calling.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with the purpose front-loaded and the confirmation caveat following, so the reader gets the primary action first. The second sentence is long and parenthetical (MCP_CONFIRM_MODE reference, nested conditions), which costs some readability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully covers the phase-1 'confirmation-required' response and the token handshake, and the schema ties 'device' back to alexa_list_devices. It stops short of describing failure modes (unreachable device, unsupported device) or whether an authenticated session is a prerequisite.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3: the schema already documents label, device, minutes, and confirmToken thoroughly, including the token's restrictions. The description restates the confirmToken lifecycle in flow terms but adds no new per-parameter meaning beyond what the schema text already provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Start an Alexa countdown timer on an Echo device') with a concrete example ('10-minute pasta timer'), which is far more specific than a tautology. It does not, however, differentiate itself from the sibling alexa_create_reminder, which an agent could plausibly confuse with a timer.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit procedural guidance for the confirmation flow: confirm in-client where supported, otherwise expect a preview plus confirmToken and only proceed on the repeat call. What is missing is routing guidance against alternatives such as alexa_create_reminder or alexa_run_builtin for timer-like behavior.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.